Uniform dyeing of viscose



Patented Apr. 26, 1932 UNITED. STATES PATENT OFFICE,

MULHEIM, ANZD RUDOLF KNOCHE, OF

LEVERKUSEN-ON-THE RHINE, GERMANY,

ASSIGNORS TO GENERAL ANILINE WORKS, 1110., OF NEW YORK, N. Y., A. CORPORA- TIOIN' OF DELAWARE UNIFORM DYEING or VISCOSE No Drawing. Application'filed November 23, 1928, Serial No. 321,513 and in Germany December 2, 1927.

The present inventiolrrelates to uniformly dyed viscose silk of different origin.

It is known that it is very difiicult to obtain even shades in the dyeing of viscose of difl'erent origin, for example of knitted artificial silk.

According to the present invention, these dlfiiculties are overcome .by dyeing viscose with a-secondary disazo dyestuff of the general formula:

O-GIH R1 -N=N N=N-n, I

80C., at which temperatures the viscose is dyed for about 3/; to 1 hour. Then the viscose is washed and dried.

The dyeings thus obtained are distinguished by their uniformity and fastness to light.

The invention is illustrated by the following examples, without being limited thereto:

wample 1.'10 parts by weight of the secondary disazo dyestufi from 4-amino-1- methylbenzene-3-sulfonic acid, 1-amino-2- ethoXy naphthalene 6-sulfonic acid and l-hydroXy-naphthalene-l-sulfonic acid having in its free state the following formula:

oc.m on g are dissolved in 300 parts of hot water.

Knitted viscose is dyed at 80 C. in this bath for about one hour in the presence of 20% of sodium sulfate and 2% of Monopole soap (calculated on the weight of the material). Thus a beautiful powerful blue dyeing is obtained, extremely uniform both in deep and pale shades and of very satisfactory fastness to light.

Example 2.-The known dyest'uff from 4-an1ino-acetanilide-3-sulfonic acid, 1-amino-' 2 ethoxynaphthalene 6 sulfonic acid and 1 acetylamino-8-hydroxynaphthalene-e-sulfonic acid having in its free state the follow- 1 ing formula:

OCzHl 80.11 on undo-.03.

viscose a beautiful uniform bluish green shade of satisfactory fastness to light.

We claim:

1. As new articles of manufacture knitted viscose dyed with a dyestufi of the general formula:

in which R stands for a radical of the benzene or naphthalene series and R stands for the radical of an aminonaphthalenesulfonic acid or an aminonaphtholsulfonic acid, the dyeings being distinguished by their uniformity and fastness to light.

2. As new articles of manufacture knitted viscose dyed with the dyestuif of the following formula:

O.CzHs $11 OHs-QN=N 03H I the blue dyeings being distinguished by their uniformity and fastness to light.

In testimony whereof We have hereunto set our hands.

WINFRID HENTRICH. [1 s.] JOSEF HILGER. [L.s.] RUDOLF KN OCHE. [L. s.] 

